Editing LVM+DRBD+LVM+KVM+LVM Resize

== info ==
 PV -> VG -> LV -> DRBD -> VG (clvmd) -> LV -> KVM Virt (that also has pv/vg/lv)

== resize LVM backing device ==

=== NODE1 ===
<source>
lvs /dev/vg_be_raid10/drbd_hopmon
  LV          VG           Attr      LSize  Pool Origin Data%  Move Log Cpy%Sync Convert
  drbd_hopmon vg_be_raid10 -wi-ao--- 9.20g   
</source>
<source>
lvresize -L+2GB /dev/vg_be_raid10/drbd_hopmon 
  Extending logical volume drbd_hopmon to 11.20 GiB
  Logical volume drbd_hopmon successfully resized
</source>

=== NODE2 ===
<source>
lvs /dev/raid10/drbd_hopmon
  LV          VG     Attr      LSize  Pool Origin Data%  Move Log Cpy%Sync Convert
  drbd_hopmon raid10 -wi-ao--- 9.20g   
</source>
<source>
 lvresize -L+2GB /dev/raid10/drbd_hopmon
  Extending logical volume drbd_hopmon to 11.20 GiB
  Logical volume drbd_hopmon successfully resized
</source>



== Resize DRBD (online) ==
<source>
 # drbdadm resize <resource>
 drbdadm resize hopmon
</source>
<source>
 #pvscan 
 #PV /dev/drbd6    VG drbd_hopmon        lvm2 [9.20 GiB / 0.20 GiB free]
 pvresize /dev/drbd6
</source>

== Resize the LVM partition on DRBD ==
* this is a clusters volume group - changes will propagate on both

<source>
lvresize -L+2GB /dev/drbd_hopmon/hopmon 
  Extending logical volume hopmon to 10.00 GiB
  Logical volume hopmon successfully resized
</source>

== Shutdown/Start KVM Host ==

* A reboot doesn't seem to notice the disk change
* shutdown the guest, then start the guest

== Resize GUEST lvm disk ==

<source>
pvs
  PV         VG        Fmt  Attr PSize PFree 
  /dev/vda2  vg_hopmon lvm2 a--  7.51g 36.00m
</source>
<source>
fdisk -u -l /dev/vda

Disk /dev/vda: 10.7 GB, 10737418240 bytes
16 heads, 63 sectors/track, 20805 cylinders, total 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000d51fa

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048     1026047      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2         1026048    16777215     7875584   8e  Linux LVM
</source>

* notice the start boundary '''1026048'''
* You will use this after you delete the parition in the next step

<source>
fdisk -u /dev/vda

Command (m for help): d
Partition number (1-4): 2

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 2
### This is where you enter in your start boundary from before
First sector (63-20971519, default 63): 1026048

Last sector, +sectors or +size{K,M,G} (1026048-20971519, default 20971519): 
Using default value 20971519
Command (m for help): t
Hex code (type L to list codes): 8e
Changed system type of partition 2 to 8e (Linux LVM)

Command (m for help): p

Disk /dev/vda: 10.7 GB, 10737418240 bytes
16 heads, 63 sectors/track, 20805 cylinders, total 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000d51fa

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048     1026047      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2         1026048    20971519     9972736   8e  Linux LVM

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
</source>


* You can try to run 'partprobe' to re-read the disk partitions.. but it may not work
* If partprobe fails you will have to reboot to allow the partition size to be apply. You can '''reboot''' this time.

<source>
pvs
  PV         VG        Fmt  Attr PSize PFree 
  /dev/vda2  vg_hopmon lvm2 a--  7.51g 36.00m
</source>
<source>
pvresize /dev/vda2
  Physical volume "/dev/vda2" changed
  1 physical volume(s) resized / 0 physical volume(s) not resized
</source>
<source>
pvs
  PV         VG        Fmt  Attr PSize PFree
  /dev/vda2  vg_hopmon lvm2 a--  9.51g 2.04g
</source>


* Now can extend the LV
<source>
lvscan 
  ACTIVE            '/dev/vg_hopmon/lv_root' [5.47 GiB] inherit
  ACTIVE            '/dev/vg_hopmon/lv_swap' [2.00 GiB] inherit
</source>
<source>
lvresize -L+2GB /dev/vg_hopmon/lv_root
  Extending logical volume lv_root to 7.47 GiB
  Logical volume lv_root successfully resized
</source>
<source>
lvscan 
  ACTIVE            '/dev/vg_hopmon/lv_root' [7.47 GiB] inherit
  ACTIVE            '/dev/vg_hopmon/lv_swap' [2.00 GiB] inherit
</source>


* Resize the filesystem
<source>
df -h /
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_hopmon-lv_root
                      5.4G  4.8G  422M  92% /
</source>
<source>
resize2fs /dev/mapper/vg_hopmon-lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_hopmon-lv_root is mounted on /; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 1
Performing an on-line resize of /dev/mapper/vg_hopmon-lv_root to 1958912 (4k) blocks.
The filesystem on /dev/mapper/vg_hopmon-lv_root is now 1958912 blocks long.
</source>
<source>
 df -h /
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_hopmon-lv_root
                      7.4G  4.8G  2.3G  68% /
</source>